Crystallization in acidic media: from nanoparticles to macrocrystals

• Javier Sanchez España ^[1]
  1. [1] Instituto Geológico y Minero de España

     Instituto Geológico y Minero de España

     Madrid, España

     
• Localización: Seminarios de la Sociedad Española de Mineralogía, ISSN-e 2659-9872, ISSN 1698-5478, Vol. 13, 1 1 (Oviedo, 4 de julio 2017), 2017 (Ejemplar dedicado a: Crystallization Under Extreme Conditions), págs. 15-34
• Idioma: inglés
• Enlaces
  • Texto completo (pdf)
• Resumen

  • Crystallization in acidic media obeys the same rules and physico-chemical principles than in any other aqueous solution. However, the composition (mineralogy), particle size and crystallinity of the solids formed in these low pH systems are strongly determined by (i) the singular water chemistry of the parent acidic solutions (highly concentrated, with presence of many dissolved metals, and usually dominated by the sulfate anion, SO4 2-), and (ii) the highly variable environmental conditions prevailing in the crystallization media (which may range from very fast to slow precipitation kinetics, from strong oversaturation to near solubility equilibrium, or from high to low density of nucleation centres). The most common mineral groups formed in acidic waters (e.g., acid mine waters, acid rock drainage) are usually metal sulfates, oxy-hydroxysulfates and sulfides, which expand largely in size (from nano-particles with diameters < 100 nm to large crystals of mm- to cm-scale) and crystalline order (nearly amorphous or short-range ordered to highly crystalline).